[SPARC] Cleanup handling of the Y/ASR registers.
- Implement copying ASR to/from GPR regs.
- Mark ASRs as non-allocatable, so it won't try to arbitrarily use
them inappropriately.
- Instead of inserting explicit WRASR/RDASR nodes in the MUL/DIV
routines, just do normal register copies.
- Also...mark div as using Y, not just writing it.
Added a test case with some code which previously died with an
assertion failure (with -O0), or produced wrong code (otherwise).
(Third time's the charm?)
Differential Revision: http://reviews.llvm.org/D10401
llvm-svn: 241686
diff --git a/llvm/test/CodeGen/SPARC/basictest.ll b/llvm/test/CodeGen/SPARC/basictest.ll
index 7b54007..3792100 100644
--- a/llvm/test/CodeGen/SPARC/basictest.ll
+++ b/llvm/test/CodeGen/SPARC/basictest.ll
@@ -38,7 +38,7 @@
; CHECK-LABEL: signed_divide:
; CHECK: sra %o0, 31, %o2
-; CHECK: wr %o2, %g0, %y
+; CHECK: wr %g0, %o2, %y
; CHECK: sdiv %o0, %o1, %o0
define i32 @signed_divide(i32 %a, i32 %b) {
%r = sdiv i32 %a, %b
diff --git a/llvm/test/CodeGen/SPARC/multiple-div.ll b/llvm/test/CodeGen/SPARC/multiple-div.ll
new file mode 100644
index 0000000..6934f69
--- /dev/null
+++ b/llvm/test/CodeGen/SPARC/multiple-div.ll
@@ -0,0 +1,21 @@
+; RUN: llc < %s -march=sparc | FileCheck %s
+; RUN: llc -O0 < %s -march=sparc | FileCheck %s
+
+;; llc -O0 used to try to spill Y to the stack, which isn't possible,
+;; and then crashed. Additionally, in -O1, it would omit the second
+;; apparently-redundant wr to %y, which is not actually redundant
+;; because the spec says to treat %y as potentially-written by udiv.
+
+; CHECK-LABEL: two_divides:
+; CHECK: wr %g0, %g0, %y
+; CHECK: udiv
+; CHECK: wr %g0, %g0, %y
+; CHECK: udiv
+; CHECK: add
+
+define i32 @two_divides(i32 %a, i32 %b) {
+ %r = udiv i32 %a, %b
+ %r2 = udiv i32 %b, %a
+ %r3 = add i32 %r, %r2
+ ret i32 %r3
+}